Cinematograph projector fire trap



Sept. 3, 1940. GLYNN 2,213,466

CINEMATOGRAPH PROJECTOR FIRE TRAP Filed Jan. 3, 1938 2 Sheets-Sheet l Sept. 3, 1940. GLYNN 2,213,466

CINEMATOGRAPH PROJECTOR FIRE TRAP Filed Jan. 5, 1938 2 Sheets-Sheet 2 Z0 Z7 60 Z? 56 J2 as i g mqunu L26 fivmvron T. f GLYNN Patented Sept. 3, 1940 UNITED STATES PATENT OFFICE Thomas Edward Glynn, Saskatoon, Saskatchewan, Canada Application January 3, 1938, Serial No. 183,205

7 Claims.-

My invention relates to improvements in cinematograph fire traps, an object of this inven tion being to provide a device of the character herewithin described by the use of which a fire started in a cinematograph projector between the upper and lower film magazines through the ignition of that portion of the film strip which is passing from the one magazine to the other may be prevented from spreading to either magazine by sealing ofi the same from the force of the fire.

A further object of my invention is to provide a device of the character herewithin described by which the ignited portion of the film is severed from the roll remaining in either one of the.

magazines.

A further object of my invention is to provide a device of the character herewithin described which may be located within either one or both of the film magazines by being secured to the circumscribing wall thereof, or which may be located in any position between the upper and lower film magazine.

A further object of my invention is to provide a device of the character herewithin described which is actuated by the fusion of a strand of material extending between the flanges of one of the film sprockets, this action causing a number of spring catches to move outwardly, thereby grounding a current which actuates a solenoid, which in turn releases a spring-held cutting knife which severs the portion of the film between the film magazines from that which is within the same and seals the contents of the said magazine.

A further object of my invention is to provide a device of the character herewithin described which is of simplified construction, is simple to install and which cannot easily become out of order.

With the above more important objects in view and such other minor objects as may appear the specification proceeds, my invention consists essentially in the arrangement and construction of parts all as hereinafter more particularly described, reference being had to the accompany-- ing drawings, in which:

Fig. 1 is a side view of a cinematograph projector showing a portion of the upper and lower film magazines, my film cutting assembly being shown partly in section with part of the projector itself being also shown in section.

Fig. 2 is a longitudinal cross section of my film cutting assembly.

Fig. 3 is a plan view of my film cutting assembly.

Fig. 4 is a longitudinal section of my film sprocket used in association with the film cutting assembly and solenoid.

In the drawings like characters of reference indicate corresponding parts in the different figures.

My invention consists of a cutting assembly A, a solenoid assembly B, and a specific form of film sprocket assembly C, and of these three parts I will first describe my cutting assembly.

This consists of a cutter block l, which is suitably secured as by means of the bolts 2 to the circumscribing wall of one or other of the film magazines 3, although I would mention here that this assembly may, if desired, be located at any convenient point within the film chamber 4, preferably at one end or the other thereof.

Extending along the sides of the cutter block is a pair of cutter guides 5 and 6, a projecting flange portion 1 extending thereover to prevent dislodgment of the cutter later to be described.

Extending across the forward end 8 of the cutter block and spaced from the base plate 5 thereof by means of a spacing block so of the configuration clearly illustrated by phantom lines in Fig. 3 of the drawings accompanying this specification is a cutter plate ll provided upon either side with brackets 32 between which is mounted for rotation a film roller i3, which assists in guiding the strip of film i l through a slot 15 clearly illustrated in Fig. 3 of the drawings accompanying this specification, formed upon the plate 9.

My cutter it is provided with an obliquely disposed cutting edge l! and with side members is and 89 clearly illustrated in Fig. 3 of the drawings accompanying this specification which are designed to run within the recesses formed between the flanges l and the edges of the base plate 9.

To the rear end of my cutter is attached a block 28, provided with a pair of orifices 2i, through each of which extends a spring guide 22, these spring guides being secured upon an end wall 23, secured to the rear end of the cutter block and extending upwardly thereacross. A cutter tension spring 2& extends around each of the members 22 between the portions 2E! and 23 so that the tendency is for the cutter l 6 to be forced to the left with respect to Figure 3 of the drawings accompanying this specification, thereby cutting the film M passing through the slot [5 and sealing the latter.

Upstanding bearings are provided upon the portion 20 in .a substantially central position thereupon, a pivoted cutter lock 26 being secured by means of a pin 21 passing therethrough and extending between the bearings 25, this look being of the configuration clearly illustrated in Figs. 2 and 3 of the drawings accompanying this specification, and when the cutter is held back in the position shown it will be seen that the lock 26 engages with a stationary catch 21, secured in alignment with the look upon the upper surface of the end-wall 23.

Adjacent one end of the member 20 is an insulating block 28, the same being suitably secured to the cover I6 and within which is a spring terminal 29, the terminal being provided with an enlarged head 30, a light spring 3!, surrounding the stem of the terminal and bearing at one end against the head and at the other end against the block. Secured to the member 5 is a second insulating block 32, the member 5 being recessed at this point to receive the same, the block itself being of the configuration clearly illustrated in Figure 3 of the drawings accompanying this specification.

A solenoid lead 33 and a collector ring lead 34 extend up to the block 32 terminating thereat in a solenoid lead terminal 35 and a collector ring lead terminal 35, the two terminals extending through the block 32 but being insulated from each other, the exterior faces thereof being in alignment so that the head 30 of the spring terminal 29 may bear against both of these members, thereby completing an electrical connec- Iv tion at this point.

Having now described my cutter assembly I will next describe my film sprocket assembly most clearly illustrated in Fig. 4 of the drawings accompanying this specification.

In this assembly I make use of the ordinary film sprocket 3! but process the flanges 38 and 38' thereof in the manner and for the purpose now to be described. A number of drillings 39 are formed through the flange 38 adjacent the periphery thereof and into these drillings I plug a number of fusible-link pegs 43 of the configuration clearly illustrated, while somewhat larger drillings 41 are formed adjacent the periphery of the flange 38, these somewhat larger drillings, however, extending only a portion of the way through the thickness of the flange. I then continue to drill through the flange 38 with a bit of the same size as that used for the drillings 39 and I now insert into the apertures thus formed a plurality of spring-actuated fusible-link'pins 42 of the configuration clearly illustrated in Fig.

4 of the drawings accompanying this specification, from which it will be seen that the same are somewhat similar in configuration to the pegs but are provided with an encircling flange 43 against which bears alight coil spring 44, one

end of the spring bearing against the end of the enlarged drilling 4|, and it will be understood that the members 42 are free to slide within their apertures, whereas the pegs 40 are held rigidly.

I now lace a strand of fusible material 45 across the sprocket between the flanges, the material being held in the notches 46 and 4'! of the pegs and the pins respectively. 7

In connection with this fusible material I should mention that I may use a continuous laced strand or may employ a number of links of the same and in either case it should be clearly understood that the lacing is sufficiently tight or the links sufiiciently short to hold the pins 42 in the position shown in Fig. 4 of the drawings accompanying this specification, in which the springs 44 are held in compression and the outer end of each of the pins is fiush with the end of the sprocket.

The sprocket is mounted upon the usual spindle 49, which is suitably journalled in the usual bearing 55, the sprocket 31 being held fast against the spindle 43 by means of a set-screw 5|. Adjacent the sprocket and extending around the portion 52 (which may if desired be reduced in diameter for this purpose) is positioned a collar 53 of insulating material, the collar being also held fast by means of a set-screw 54. The collar 53 is recessed to receive a bronze collector ring 55, and attached to the collector ring is the opposite end of my collector ring lead 34, it being clearly understood at this point that under normal circumstances the bronze ring 55 is out of contact with the pins. 42.

Having now described my film sprocket assembly, I will next describe my solenoid assembly.

This consists of a solenoid 56 best illustrated in Fig. 1 of the drawings accompanying this specification, the same being attached to a mounting block 57 secured upon the outer surface of the circumferential wall of the film magazine 3 although it is to be understood that if desired, the solenoid may be placed in any other suitable position for the purpose of co-acting with my cutter assembly,

Through the centre of the solenoid and through a passageway formed within the bearing block 5? extends a release pin 58, the outer end of which is pointed as illustrated, the pin being normally maintained in the position clearly illustrated in the drawings accompanying this specification.

A solenoid input lead 59 extends from the solenoid to the usual main, while the solenoid.

lead 33 already described, extends between the terminal 35 and the solenoid.

Having now described the various component parts of my invention, its operation will be set forth.

In the event of a portion of the film within the film chamber 4 becoming ignited by the heat of the lamp or through other reasons, the fusible material happens, the pins 42 will shoot out under. the influence of the springs 44 and will engage and make contact with the collector ring 55, whereby current passing through the lead 34 will be grounded upon the metal part of the projector, which will have the effect of energising the solenoid, thereby causing the release pin 58 to move to the left, thereby releasing the lock 26 from the catch 27, will cause the cutter Hi to snap across and sever the film and seal the slot 9. As soon as this happens it is obvious that contact will be broken between the terminals 35 and 36 whereupon the current will fiow normally again through the solenoid.

When it is desired to reset the cutter assembly the sprocket assembly must be re-fused or if a pair of sprocket assemblies are being used they will both be re-fused. Alternatively a new as sembly or assemblies may be inserted. The cutter is then drawn back again to the position illustrated in the drawings accompanying this specification, after which the lock will be brought into engagement with the stationary catch and the release pin moved to the left. The device is now again ready for an emergency.

It is obvious, of course, that when tl e pointed 45 will become severed. When this end of the release pin 58 bears against the bevelled under-side 60 of the lock 26, the same is bound to rotate upwardly about the pivot pin 21' thus automatically releasing it from the catch 21.

It should clearly be understood that while I have shown in Fig. 1 of the drawings accompanying this specification only one cutting mechanism A located within the upper film magazine 3, I may if I so desire place one of these mechanisms in the lower film magazine as well. In this case, an additional sprocket assembly C may be employed adjacent the lower end of the film chamber l, or, on the other hand, the one sprocket assembly may be employed to actuate the two cutting mechanisms. It should be furthermore clearly understood that if desired my cutting mechanism or mechanisms may be placed without the film magazine as upon the exterior surface thereof or within and adjacent either end of the film chamber to seal ofi the ends thereof.

Since various modifications can be made in the above invention, and many apparently widely different embodiments of same, made within the scope of the claims without departing from the spirit and scope thereof, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense and I desire only such limitations placed thereon as are specifically expressed in the accompanying claims.

What I claim as my invention is:

1. In a cinematograph projector fire trap assembly and in combination with a film cutting mechanism and an adjacent solenoid, a film sprocket mechanism and an adjacent current carrying element, said film sprocket mechanism consisting of the combination with a film sprocket of a movable contact normally spaced from the said current carrying element, said contact being designed to move into contact with said element upon the ignition of a strip of film within a film chamber whereby said solenoid is energised and and said film cutting mechanism actuated to cut oil the ignited strip of film from the film within an adjacent magazine.

2. In a cinematograph projector fire trap assembly and in combination with the film cutting mechanism and an adjacent solenoid thereof, a film sprocket mechanism and an adjacent current carrying element, said film sprocket mechanism consisting of the combination with the said film sprocket of a plurality of outwardly movable spring actuated contacts extending through one of the flanges of said sprocket, and a plurality of stationary pegs secured to the opposite flange, said contacts being provided each with a recess, a strand or link of fusible material extending across the body of said sprocket, around said pegs and through the recess within each of said contacts normally to restrain said contacts against outward movement, said contacts being free to spring outwardly upon the fusing of said link or strand to make contact with said current carrying element, thereby energising said solenoid to actuate said film cutting mechanism.

3. In combination with an electrically actuated film cutting assembly for a cinematograph projector, a rotatable film engaging sprocket mechanism, comprising a sprocket, a movable contact upon said sprocket, a fusible element attached to said contact, and an adjacent contact whereby ignition of a strip of film in the film chamber of said projector releases said movable contact against said adjacent contact thereby actuating said cutting assembly.

4. A cinematograph projector fire trap assembly comprising in combination, a film cutting mechanism, said mechanism comprising a body portion mounted within a film magazine of a projector and having a slot formed therein through which a strip of film may pass, a cutter slidably mounted upon said body portion for movement across said slot, an obliquely disposed cutting edge formed upon the forward edge of said cutter, guide rods secured at one end thereof to said body portion, the forward ends of said rods projecting slidably through apertures provided in a portion of said cutter, coil springs mounted about said guide rods and extending between said cutter and said body portion, releasable locking means for holding said cutter normally in a retracted position against the tension of said springs, comprising a stationary catch secured to said body portion, a movable catch engageable with said stationary catch and pivotally mounted upon said cutter, the free end of said movable catch being sharply bevelled, a solenoid secured adjacent said body portion and having its longitudinal axis in alignment with the bevelled end of said movable catch, a releasing pin slidably positioned within said solenoid, the forward end of said pin being pointed and positioned adjacent the bevelled end of said movable catch, whereby said movable catch is released and said springs permitted to force said cutter across said slot when said solenoid is energised, a solenoid circuit closing mechanism positioned within the film chamber of said projector, said mechanism being designed to close the solenoid circuit upon ignition of a strip of film in said chamber.

5. The device as defined in claim 4 in which said circuit closing mechanism comprises a rotatable film engaging sprocket mechanism, a heat responsive element comprising part of said mechanism, whereby said mechanism is actuated to close the circuit of said film cutting assembly upon ignition of a strip of film in the film chamber of said projector.

6. In combination with the device as defined in claim 4, a solenoid circuit opening mechanism, said mechanism being automatically actuated upon release of said cutter.

'7. The device as defined in claim 2 in which said current carrying element comprises an annular ring positioned concentrically with said sprocket and insulated from the body of said projector, the circuit extending from a source of electrical energy through said solenoid and to said element, being grounded upon fusion of said link of fusible material and consequent contact of said movable contacts with said ring.

THOMAS EDWARD GLYNN. 

